Cat 6 In Same Conduit with 120 Volt Power

It does!

Unless it's POE.

-Hal
Fellon: see 800.2 and its def of communications circuit.
Negatory. Read through this article and it will make sense:


(Hal: we had this discussion before and I posted the same article and you stated you dont believe the author. Fine.
 
That does not seem to be the case because they call out 90.2 (B) so FIOS up to the ONT would be on the utility.

840.2 then specifically defines the communications circuit and calls out data.
View attachment 2555364



Where in 725 does it reference UTP or network cables?

Its quite confusing and convoluted. I am not defending the NEC here, they should just throw out most of the 700-800 articles, they are completely atrocious and outdated and just awful, and start over, but the link in post #41 explains it.
 

mikeames

Senior Member
Location
Germantown MD
Occupation
Teacher - Master Electrician - 2017 NEC
After going back and fourth I came to the same conclusion. I read 800.133 , 745 and other sections, found similar definitions etc... then figured It must be me that didn't have the experience to follow it. I appreciate your feedback.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
Negatory. Read through this article and it will make sense:


(Hal: we had this discussion before and I posted the same article and you stated you dont believe the author. Fine.

Communications Circuit
: The circuit that extends voice, audio, video, data, interactive services, telegraph (except radio), outside wiring for fire alarm, and burglar alarm from the communications utility to the customer’s communications equipment up to and including terminal equipment such as a telephone, fax machine, or answering machine.

In typical NEC language, this definition is not written in a form that would make it easy to understand.
Oh I can understand it just fine. I just don't agree with it. The crux seems to be in the wording "The circuit that extends... from the communications utility to the customer’s communications equipment".

Maybe back in 1940 when telephones were directly connected to the phone company outside plant that made sense. Now we have all nature of equipment in between the outside utility and the building premise wiring. The premise wiring is not in any way connected to the "communications utility" and originates on equipment within the building. In the 2011 handbook (the latest handbook I have) Article 800 has illustrations and references to PBXs, yet the NEC code panel fails to recognize the distinction. There is no extending!

We have voice and data supplied to the building which is processed and "value added" by customer owned equipment. The only item that passes through is the actual voice and data.

The communications utility wiring STOPS at the customer owned equipment. The premises wiring BEGINS or ORIGINATES at the customer's equipment.

Now lets look at data wiring. In all cases the data network is connected to the outside world just like voice and in many cases in exactly the same way. The utility's outside plant terminates on a modem, ONT etc, which is connected to the customer supplied router, server and switches then to the premise wiring. Once again:

The communications utility wiring STOPS at the customer owned equipment. The premises wiring BEGINS or ORIGINATES at the customer's equipment.

So if a PBX, in the NEC's mind doesn't change their definition and you still want to buy the argument that an Article 800 communications circuit is "The circuit that extends voice, audio, video, data, interactive services, telegraph (except radio), outside wiring for fire alarm, and burglar alarm from the communications utility to the customer’s communications equipment up to and including terminal equipment such as a telephone, fax machine, or answering machine" it would have to include Ethernet network premises wiring.

Thing is the author of that white paper is entitled to his interpretation, and that's just it- his interpretation. I'm not buying it. I just gave you mine.

...they should just throw out most of the 700-800 articles, they are completely atrocious and outdated and just awful, and start over...
I think if the code making panel put as much effort into 725-800 as they do with AFCIs and GFCIs we would have something up to date and understandable.

-Hal
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
What Code article covers RS-232 and RS-485 data communication wiring? Is it a class 2 circuit? Can serial data communication work on non twisted wiring like tray cable?
RS-232 specifically uses single ended rather than differential signals, so twisted pair is not a useful option. Instead use a pair of drivers the using a different signalling standard over the cable.

Sent from my Pixel 4a using Tapatalk
 

tortuga

Senior Member
Location
Oregon
Occupation
Electrical Design
I think what that article Fellon posted is getting at is if the power for the data/phone/CATV signal originates from outside the building its art 800, if the signal power comes from a power supply its art 725.
A router / modem / switch is kinda like a speeratly derived system.
Its an interesting article 7 years old. He is a local EE here i'll ask him if he still agrees with it in the 2020 code.
 

mikeames

Senior Member
Location
Germantown MD
Occupation
Teacher - Master Electrician - 2017 NEC
I think what that article Fellon posted is getting at is if the power for the data/phone/CATV signal originates from outside the building its art 800, if the signal power comes from a power supply its art 725.
A router / modem / switch is kinda like a speeratly derived system.
Its an interesting article 7 years old. He is a local EE here i'll ask him if he still agrees with it in the 2020 code.
With that assumption, then the same cable running to the same outlet, terminating on the same tombstone would fall under two different installation requirements depending on if you used POTs or VOIP.

I dont think the article provides anything we haven't already discussed here. No new info. Like others said and everyone agrees, the NEC not clear here. It's a huge shortfall for the NEC and is surprising that there is not specific wording regarding these topics given the NEC has expanded in many other areas that some consider questionable.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
I think what that article Fellon posted is getting at is if the power for the data/phone/CATV signal originates from outside the building its art 800, if the signal power comes from a power supply its art 725.
With plain old ethernet THERE IS NO POWER. Why the hell would they want ethernet ports on equipment labeled as to the class of wiring required? This just goes to show the level of understanding (actually ignorance) they have of technology systems. There are plenty of communications systems where there is no real power involved.

On the other hand, why isn't there a section in 725 that covers Power Over Ethernet (POE). How many years has it been around now? It's like they never heard of it.

It's a huge shortfall for the NEC and is surprising that there is not specific wording regarding these topics given the NEC has expanded in many other areas that some consider questionable.
I think the reason is that technology companies don't really care about the NEC. Whether data wiring is Art 725 or 800 in actuality makes no difference. If the technology companies profits were impacted by the NEC you can bet they would manipulate changes.

-Hal
 

tortuga

Senior Member
Location
Oregon
Occupation
Electrical Design
With that assumption, then the same cable running to the same outlet, terminating on the same tombstone would fall under two different installation requirements depending on if you used POTs or VOIP.

I dont think the article provides anything we haven't already discussed here. No new info. Like others said and everyone agrees, the NEC not clear here. It's a huge shortfall for the NEC and is surprising that there is not specific wording regarding these topics given the NEC has expanded in many other areas that some consider questionable.
Well it was a refresher for me, thanks agian to Fellon for that. It will make a great class handout.
I got in touch with Tim to get his permission to use that in class.

With plain old ethernet THERE IS NO POWER. Why the hell would they want ethernet ports on equipment labeled as to the class of wiring required? This just goes to show the level of understanding (actually ignorance) they have of technology systems. There are plenty of communications systems where there is no real power involved.

On the other hand, why isn't there a section in 725 that covers Power Over Ethernet (POE). How many years has it been around now? It's like they never heard of it.



I think the reason is that technology companies don't really care about the NEC. Whether data wiring is Art 725 or 800 in actuality makes no difference. If the technology companies profits were impacted by the NEC you can bet they would manipulate changes.

-Hal
The code requirements for POE are in Article 725 in 2017, so as Tim said "it made it a lot easier to make the argument to folks that our Ethernet data circuits are all covered under Article 725 unless they extend beyond a building. If they extend beyond a building they are still 725 but you have to install them with protection per 800. "
 

mikeames

Senior Member
Location
Germantown MD
Occupation
Teacher - Master Electrician - 2017 NEC
On the other hand, why isn't there a section in 725 that covers Power Over Ethernet (POE). How many years has it been around now? It's like they never heard of it.



-Hal
EXACTLY especially since companies are making and using POE lighting. It kind of does but not nearly as clearly as it should. Heck even Mike has a video on it. I have installed and used CAT6A LP cable.

 
Last edited:

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
The code requirements for POE are in Article 725 in 2017, so as Tim said "it made it a lot easier to make the argument to folks that our Ethernet data circuits are all covered under Article 725
Take a look at 725.1 and tell me how it covers data.

725.1 Scope.
This article covers remote-control, signaling,
and power-limited circuits that are not an integral part of a
device or of utilization equipment.
With your thinking you could say that all microphone cables belong in 725 too because they can sometimes have 48V phantom power on them.

What you need to understand is:

IF the cable has power on it, it Art 725 applies.
IF there is no power it falls under 800.

Why is that so hard to understand? Probably because there is no section in 725 specifically addressing POE as there should be that clarifies it. Again, how long has it been in existence? And as @mikeames points out, it's now being expanded into powering and control of lighting.

Also, 800 needs to be rewritten, particularly to remove the confusing assumption that communications circuits must originate from a utility or service provider or it's not a communications circuit. If they don't originate from a utility or service provider what are they? You can't just automatically say they are 725 because that's the only other place for them.


Communications Circuit. The circuit that extends voice, audio,
video, data, interactive services, telegraph (except radio),
outside wiring for fire alarm and burglar alarm from the
communications utility to the customer's communications
equipment up to and including terminal equipment such as a
telephone, fax machine, or answering machine.
Fax or answering machine? 🤣 Hello 80's!

-Hal


 

tortuga

Senior Member
Location
Oregon
Occupation
Electrical Design
Take a look at 725.1 and tell me how it covers data.
OK Like I say, I am no expert, and your rationale makes sense to me,
I think of signaling circuits as your 24 VAC A/C compressor contactors, fire alarm etc, generator start...
But any data circuit needs some voltage, right? And would that not be power-limited?
I think of communications, ethernet or digital data as typically 1/2 - 5 volts. POTS can have 105 V for ringing I know.
RS-485 can go miles so that must have a few volts?
just to keep exploring the code, here it is:

2017 NEC said:
725.1 Scope. This article covers remote-control, signaling, and
power-limited circuits
that are not an integral part of a device or
of utilization equipment.
Informational Note: The circuits described herein are character-
ized by usage and electrical power limitations that differentiate
them from electric light and power circuits; therefore, alternative
requirements to those of Chapters 1 through 4 are given with
regard to minimum wire sizes, ampacity adjustment and correc-
tion factors, overcurrent protection, insulation requirements, and
wiring methods and materials.
I think the article and Fellons point was this:
2017 NEC said:
645.3(D)
Electrical Classification of Data Circuits. Section 725.121(A)(4) shall apply to the electrical classification
of listed information technology equipment signaling circuits.

2017 NEC said:
840.160 Powering Circuits. Communications cables, in addition
to carrying the communications circuit, shall also be permitted to
carry circuits for powering communications equipment. Where the
power supplied over a communications cable to communications
equipment is greater than 60 watts, communication cables and the
power circuit shall comply with 725.144 where communications
cables are used in place of Class 2 and Class 3 cables.
 

tortuga

Senior Member
Location
Oregon
Occupation
Electrical Design
EXACTLY especially since companies are making and using POE lighting. It kind of does but not nearly as clearly as it should. Heck even Mike has a video on it. I have installed and used CAT6A LP cable.

Not sure what code you guys are on its here in the 2017;
2017 NEC said:
725.144 Transmission of Power and Data. The requirements
of 725.144(A) and (B) shall apply to Class 2 and Class 3 circuits
that transmit power and data to a powered device. The require-
ments of Parts I and III of Article 725 and 300.11 shall apply to
Class 2 and Class 3 circuits that transmit power and data. The
conductors that carry power for the data circuits shall be cop-
per. The current in the power circuit shall not exceed the current
limitation of the connectors.
More in the 2020
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
But any data circuit needs some voltage, right? And would that not be power-limited?
I think of communications, ethernet or digital data as typically 1/2 - 5 volts.
Yes, but I don't think it's even measurable with a meter. How about audio lines? The whole purpose of 725 is the safety of the circuits and wiring it covers with regard to fire and electrocution. With communications circuits there is no concern for this.

POTS can have 105 V for ringing
And where is POTS included? Art 800!

Not sure what code you guys are on its here in the 2017;
Ahh, OK. I see 725.144 now. Hang it on the end of 725 where you wouldn't look for it. That whole section should replace
725.121(A)(4).

Yes, that's POE.

-Hal
 

mikeames

Senior Member
Location
Germantown MD
Occupation
Teacher - Master Electrician - 2017 NEC
Stuff is there but its still a mess and there is still a lot of grey area. Its all over the place.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
The code requirements for POE are in Article 725 in 2017, so as Tim said "it made it a lot easier to make the argument to folks that our Ethernet data circuits are all covered under Article 725
Note that I'm not conceding anything by what I said above or to Tim. Ethernet that also carries power is 725. Plain old Ethernet is 800.

-Hal
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Note that I'm not conceding anything by what I said above or to Tim. Ethernet that also carries power is 725. Plain old Ethernet is 800.

-Hal
Both are 725.

725.121 Power Sources for Class 2 and Class 3 Circuits.
(A) Power Source. The power source for a Class 2 or a Class 3
circuit shall be as specified in 725.121(A)(1), (A)(2), (A)(3),
(A)(4), or (A)(5):
Informational Note No. 1: Informational Note Figure 725.121,
No. 1 illustrates the relationships between Class 2 or Class 3
power sources, their supply, and the Class 2 or Class 3 circuits.
Informational Note No. 2: Table 11(A) and Table 11(B) in
Chapter 9 provide the requirements for listed Class 2 and
Class 3 power sources.
(1) A listed Class 2 or Class 3 transformer
(2) A listed Class 2 or Class 3 power supply
(3) Other listed equipment marked to identify the Class 2 or
Class 3 power source
Exception No. 1 to (3): Thermocouples shall not require listing as a
Class 2 power source.
Exception No. 2 to (3): Limited power circuits of listed equipment where
these circuits have energy levels rated at or below the limits established
in Chapter 9, Table 11(A) and Table 11(B).
Informational Note: Examples of other listed equipment are as
follows:
***
(4) Listed audio/video information technology (computer),
communications, and industrial equipment limited-power
circuits.
Informational Note: One way to determine applicable
requirements for listing of information technology
(computer) equipment is to refer to UL 60950-1-2011,
Standard for Safety of Information Technology Equipment.
Another way to determine applicable requirements for
listing of audio/video, information and communication
technology equipment is to refer to UL 62368-1-2014,
Safety of audio/video, information and communication technology
equipment. Typically such circuits are used to interconnect
data circuits for the purpose of exchanging
information data. One way to determine applicable
requirements for listing of industrial equipment is to refer
to UL 61010-2-201, Safety requirements for electrical equipment
for measurement, control, and laboratory use –Part 2-201:
Particular requirements for control equipment, and/or
UL 61800-5-1, Adjustable speed electrical power drive systems –
Part 5-1: Safety requirements –Electrical, thermal and energy.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
Both are 725
Looking at the 17' now, where apparently that's from, I see they revised it again trying to defend it being in 725. There is no way they are going to convince me that data and audio signals involve some kind of power which is what 725 is all about. Its communications. It might as well be an unconnected cable. (What Article would that fall under?)

But let's say that we concede that 725 covers data wiring. What difference would it make if it were covered by 800? What if anything is there in 725 relating to the installation and use of data wiring that's not also in 800? Is there any requirement in 800 that would prohibit or limit the installation or use of data wiring?

From what I can see, the only thing that applies to data wiring in either Article is the boiler plate which is the same for both Articles. So I guess from a practical standpoint it doesn't matter where it is. If you want to be accurate it's another matter.

-Hal
 

mikeames

Senior Member
Location
Germantown MD
Occupation
Teacher - Master Electrician - 2017 NEC
There is no way they are going to convince me that data and audio signals involve some kind of power which is what 725 is all about. Its communications. It might as well be an unconnected cable. (What Article would that fall under?)
I totally agree. They use Class 2- 3 as a blanket and simply ignore ethernet and network like they are unusual installs that can be mushed into low power class 2 and 3. It like it's an after thought. People justify it by saying "Well inside the switch and router there is a power supply". Of course there is. There's a power supply unit in a cell phone as well. Are we now going to consider the power supply inside products now? That's why its not clear. The code is very specific in many unusual things. It would make sense if the code was far more specific about networking cables without lumping it in to limited power.
 
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